I had this happen last night (Zombie/Wizard vs Ninja-Alien). If you read what the card states, they should be relatively self-explanatory. If you're confused, you're likely over thinking it.

With TCTGY, for any minion to be played (Base, or Extra minion), you would have the choice of a card in your hand, or a card from the discard pile.

If you could only use that ability once per turn, it would have stated "Once per turn, you may ....". Or if you got this as an additional action, it would have stated "You may play an extra minion from your discard pile" (this was my mis-reading).

This came up in a game I was playing over the weekend, and this is how we treated it as well.

The craziness is that I was Zombies/Robots. My pirate opponent would Broadside me to kill my minions, and all five or six of them would pop out of the discard pile on the next turn to the base with "They're Coming to Get You". (Robots chaining back from the grave is a sick combo!)